Open service technology is a technology of defining abstract application program interfaces (APIs) for fixed/mobile telecommunication network capabilities such as a fixed/mobile call control function, short messaging and multimedia messaging transmitting/receiving functions and acquiring of a subscriber's location information to provide an environment in which a third party service provider can easily develop and rapidly deploy various application services by using those APIs without taking care of the detailed procedure and processing happened in the communication network.
An open service gateway is a necessary element for a next generation open network, which provides services using standardized open APIs irrespective of the network type such as fixed network, mobile network and IP network. The open service gateway abstracts various network capabilities, such as call control, call status monitoring, charging, location information and presence information and so on and provides the abstracted functions in the form of a service capability feature(SCF) that exposes a service interface existing in the open service gateway. Although communication network service providing systems that have been developed up to now are dependent on a specific single network, the open service gateway system provides communication services through the same open API in various networks.
Open API technology is established by Parlay Group and published as a standard such as 3GP, ETSI, 3GPP2 through activity of Joint Working Group (JWG) with members of 3GPP that is a standard group of third generation mobile communications.
Capability of communication network which can be used through the open API includes call processing, transmitting/receiving a short message/multimedia message, providing position information, charging and account management, presence and availability information and is continuously extended.
Multimedia messaging API defined in 3GPP TS 29.199-01 is originally designed to send any kind of multimedia messages to desired destination terminal by simply invoking the multimedia message API like sendMessage( )irrespective of the different message transportation infrastructures like SMSC(Short Message Service Center), MMRS(Multimedia Message Relay Server) or other message transportation system. So, the standard specification does not mandate the only use of MMS infrastructure.
However, Most of the existing systems which implemented the Multimedia messaging API translate the incoming message request into a message in the form of a MMS message The reason why the systems do not use different infrastructures depending on characteristics and environments of common carriers and usually operate in connection with the MMS infrastructure is that short messaging web service standard 3GPP TS 29. 199-04 is separately defined in the case of short messaging.
In general, MMS means a third generation multimedia messaging service which can construct a new value-added multimedia message using individual contents such as text, images, video clips or music and transmit the new value-added multimedia message through various services.
However, the original purpose of the multimedia messaging API is to transmit the requested messages from application server to a destination terminal by providing and using the same interface irrespective of whether the message can be translated into SMS or MMS.
Furthermore, many SMS infrastructures have been previously installed, and thus expenses can be reduced when the SMS infrastructures are used. Moreover, when a destination terminal is a short messaging dedicated terminal, it is required to transmit messages to the destination terminal using the SMS infrastructure.